The Validity of the 16-Item Version of the Prodromal Questionnaire (PQ-16) to Screen for Ultra High Risk of Developing Psychosis in the General Help-Seeking Population

In order to bring about implementation of routine screening for psychosis risk, a brief version of the Prodromal Questionnaire (PQ; Loewy et al., 2005) was developed and tested in a general help-seeking population. We assessed a consecutive patient sample of 3533 young adults who were help-seeking for nonpsychotic disorders at the secondary mental health services in the Hague with the PQ. We performed logistic regression analyses and CHi-squared Automatic Interaction Detector decision tree analysis to shorten the original 92 items. Receiver operating characteristic curves were used to examine the psychometric properties of the PQ-16. In the general help-seeking population, a cutoff score of 6 or more positively answered items on the 16-item version of the PQ produced correct classification of Comprehensive Assessment of At-Risk Mental State (Yung et al., 2005) psychosis risk/clinical psychosis in 44% of the cases, distinguishing Comprehensive Assessment of At-Risk Mental States (CAARMS) diagnosis from no CAARMS diagnosis with high sensitivity (87%) and specificity (87%). These results were comparable to the PQ-92. The PQ-16 is a good self-report screen for use in secondary mental health care services to select subjects for interviewing for psychosis risk. The low number of items makes it quite appropriate for screening large help-seeking populations, thus enhancing the feasibility of detection and treatment of ultra high-risk patients in routine mental health services. © The Author 2012

The association between migrant status and transition in an ultra-high risk for psychosis population

Purpose: Migrant status is one of the most replicated and robust risk factors for developing a psychotic disorder. This study aimed to determine whether migrant status in people identified as Ultra-High Risk for Psychosis (UHR) was associated with risk of transitioning to a full-threshold psychotic disorder. Methods: Hazard ratios for the risk of transition were calculated from five large UHR cohorts (n = 2166) and were used to conduct a meta-analysis using the generic inverse-variance method using a random-effects model. Results: 2166 UHR young people, with a mean age of 19.1 years (SD ± 4.5) were included, of whom 221 (10.7%) were first-generation migrants. A total of 357 young people transitioned to psychosis over a median follow-up time of 417 days (I.Q.R.147–756 days), representing 17.0% of the cohort. The risk of transition to a full-threshold disorder was not increased for first-generation migrants, (HR = 1.08, 95% CI 0.62–1.89); however, there was a high level of heterogeneity between studies The hazard ratio for second-generation migrants to transition to a full-threshold psychotic disorder compared to the remainder of the native-born population was 1.03 (95% CI 0.70–1.51). Conclusions: This meta-analysis did not find a statistically significant association between migrant status and an increased risk for transition to a full-threshold psychotic disorder; however, several methodological issues could explain this finding. Further research should focus on examining the risk of specific migrant groups and also ensuring that migrant populations are adequately represented within UHR clinics

The P3 event-related potential in young recent-onset schizophrenic patients

In schizophrenic patients, the amplitude of the P3 event-related potential (ERP) is usually decreased and the latency is often prolonged. Most ERP studies have compared schizophrenic patients with chronic illness or in mixed age groups with age-matched control subjects. However, P3 latency and amplitude change with age, and P3 latency increases more rapidly in schizophrenic patients than in control subjects. To investigate whether mixed age groups and chronic illness have been determining factors in ERP results, P3 was measured in 15 young patients (mean age 21.6 years) with recent-onset schizophrenia and compared with age-matched controls. P3 amplitudes were decreased in the schizophrenic group compared with the control group. P3 latencies were less significantly prolonged in the schizophrenic group than in other studies. Furthermore, in an exploratory study, the ERPs resulting from application of the irrelevant tones in some schizophrenic patients demonstrated ERP activity at latencies of 250-600 ms, while little or no activity was present at these latencies in control subjects. It is hypothesized that a defect in inhibition of incoming sensory information in the nucleus reticularis thalami may play a role in the pathogenesis of schizophrenia. Such a defect could result in a dysfunctional filter function of external stimuli and may therefore affect the social and psychological functioning of the patient. (C) 1998 Rapid Science Lt

Early intervention in patients at ultra high risk of psychosis: benefits and risks.

Objective: Prediction of transition to psychosis in the prodromal phase of schizophrenia has raised interest in intervention prior to the onset of frank psychosis. The aim of this review was to examine whether interventions in the prodromal phase have a favourable benefit/risk ratio. Method: A literature search in PubMed, EMBASE and PsycINFO was performed. Results: Three randomized clinical trials with antipsychotic medication and/or cognitive behavioural therapy as clinical intervention suggested a positive effect at the end of treatment, but no significant differences were found at the end of follow-up periods from 1 to 4 years. Naturalistic studies present a hypothesis about a possible preventive effect of antidepressive medication. The results of eight other studies are more difficult to interpret. Side-effects of antipsychotic medication and non-adherence with medication are essential problems. Conclusion: At the present time, the data concerning the benefits and risks do not justify prodromal intervention as standard clinical practice. © 2009 John Wiley & Sons A/S